Although arthropods are important viral vectors, the biodiversity of arthropod viruses, as well as the role that arthropods have played in viral origins and evolution, is unclear. Through RNA ...sequencing of 70 arthropod species we discovered 112 novel viruses that appear to be ancestral to much of the documented genetic diversity of negative-sense RNA viruses, a number of which are also present as endogenous genomic copies. With this greatly enriched diversity we revealed that arthropods contain viruses that fall basal to major virus groups, including the vertebrate-specific arenaviruses, filoviruses, hantaviruses, influenza viruses, lyssaviruses, and paramyxoviruses. We similarly documented a remarkable diversity of genome structures in arthropod viruses, including a putative circular form, that sheds new light on the evolution of genome organization. Hence, arthropods are a major reservoir of viral genetic diversity and have likely been central to viral evolution.
Our understanding of the diversity and evolution of vertebrate RNA viruses is largely limited to those found in mammalian and avian hosts and associated with overt disease. Here, using a large-scale ...meta-transcriptomic approach, we discover 214 vertebrate-associated viruses in reptiles, amphibians, lungfish, ray-finned fish, cartilaginous fish and jawless fish. The newly discovered viruses appear in every family or genus of RNA virus associated with vertebrate infection, including those containing human pathogens such as influenza virus, the Arenaviridae and Filoviridae families, and have branching orders that broadly reflected the phylogenetic history of their hosts. We establish a long evolutionary history for most groups of vertebrate RNA virus, and support this by evaluating evolutionary timescales using dated orthologous endogenous virus elements. We also identify new vertebrate-specific RNA viruses and genome architectures, and re-evaluate the evolution of vector-borne RNA viruses. In summary, this study reveals diverse virus-host associations across the entire evolutionary history of the vertebrates.
Emerging infectious diseases, such as severe acute respiratory syndrome (SARS) and Zika virus disease, present a major threat to public health
. Despite intense research efforts, how, when and where ...new diseases appear are still a source of considerable uncertainty. A severe respiratory disease was recently reported in Wuhan, Hubei province, China. As of 25 January 2020, at least 1,975 cases had been reported since the first patient was hospitalized on 12 December 2019. Epidemiological investigations have suggested that the outbreak was associated with a seafood market in Wuhan. Here we study a single patient who was a worker at the market and who was admitted to the Central Hospital of Wuhan on 26 December 2019 while experiencing a severe respiratory syndrome that included fever, dizziness and a cough. Metagenomic RNA sequencing
of a sample of bronchoalveolar lavage fluid from the patient identified a new RNA virus strain from the family Coronaviridae, which is designated here 'WH-Human 1' coronavirus (and has also been referred to as '2019-nCoV'). Phylogenetic analysis of the complete viral genome (29,903 nucleotides) revealed that the virus was most closely related (89.1% nucleotide similarity) to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus) that had previously been found in bats in China
. This outbreak highlights the ongoing ability of viral spill-over from animals to cause severe disease in humans.
The integration of porous metal-organic frameworks onto the surface of materials, for use as functional devices, is currently emerging as a promising approach for gas sensing and flexible displays. ...However, research focused on potential applications in electronic devices is in its infancy. Here we present a facile strategy by which interpenetrated, crystalline metal-organic framework films are deposited onto conductive metal-plate anodes via in situ temperature-controlled electrochemical assembly. The nanostructure of the surface as well as the thickness and uniformity of the film are well controlled. More importantly, the resulting films exhibit enhanced dielectric properties compared to traditional inorganic or organic gate dielectrics. This study demonstrates the successful implementation of the rational design of metal-organic framework thin films on conductive supports with high-performance dielectric properties.
Pythagorean fuzzy sets are powerful techniques for modeling vagueness in practice. The aim of this article is to investigate an effective means to aggregate uncertain information and then employ it ...into settling multiple criteria decision making (MCDM) problems within the Pythagorean fuzzy circumstances. To capture the nature of the reality, some special cases should be comprehensively considered. First, though correlation commonly exist among criteria, a deep insight should also be provided into some realistic situations, in which not all the criteria are interrelated to others. Besides, it is more reasonable to take the importance of the input arguments into consideration. Effected by aforementioned point, this article explores a Pythagorean fuzzy partitioned normalized weighted Bonferroni mean (PFPNWBM) operator with the combination of partitioned Bonferroni mean (BM) and normalized weighted BM operators considering Shapley fuzzy measure. Subsequently, in the context of partially known weight information, models are established to identify the optimal Shapley fuzzy measure. Moreover, integrated the PFPNWBM operator with the optimal Shapley fuzzy measure identification model, a Pythagorean fuzzy MCDM approach is designed. Finally, an illustrative example and detailed analyses are performed to demonstrate its feasibility and reliability.
Developing single‐atomic catalysts with superior selectivity and outstanding stability for CO2 electroreduction is desperately required but still challenging. Herein, confinement strategy and ...three‐dimensional (3D) nanoporous structure design strategy are combined to construct unsaturated single Ni sites (Ni‐N3) stabilized by pyridinic N‐rich interconnected carbon nanosheets. The confinement agent chitosan and its strong interaction with g‐C3N4 nanosheet are effective for dispersing Ni and restraining their agglomeration during pyrolysis, resulting in ultrastable Ni single‐atom catalyst. Due to the confinement effect and structure advantage, such designed catalyst exhibits a nearly 100% selectivity and remarkable stability for CO2 electroreduction to CO, exceeding most reported state‐of‐the‐art catalysts. Specifically, the CO Faradaic efficiency (FECO) maintains above 90% over a broad potential range (‐0.55 to ‐0.95 V vs. RHE) and reaches a maximum value of 99.6% at a relatively low potential of ‐0.67 V. More importantly, the FECO is kept above 95% within a long‐term 100 h electrolyzing. Density functional theory (DFT) calculations explain the high selectivity for CO generation is due to the high energy barrier required for hydrogen evolution on the unsaturated Ni‐N3. This work provides a new designing strategy for the construction of ultrastable and highly selective single‐atom catalysts for efficient CO2 conversion.
Unsaturated single Ni sites (Ni‐N3) anchored on pyridinic N‐rich interconnected carbon nanosheets are constructed via confinement strategy. Due to the confinement effect and structure advantage, such designed catalyst exhibits a nearly 100% selectivity and remarkable stability (100 h) for CO2 electroreduction to CO.
Viruses of the family Flaviviridae are important pathogens of humans and other animals and are currently classified into four genera. To better understand their diversity, evolutionary history, and ...genomic flexibility, we used transcriptome sequencing (RNA-seq) to search for the viruses related to the Flaviviridae in a range of potential invertebrate and vertebrate hosts. Accordingly, we recovered the full genomes of five segmented jingmenviruses and 12 distant relatives of the known Flaviviridae ("flavi-like" viruses) from a range of arthropod species. Although these viruses are highly divergent, they share a similar genomic plan and common ancestry with the Flaviviridae in the NS3 and NS5 regions. Remarkably, although these viruses fill in major gaps in the phylogenetic diversity of the Flaviviridae, genomic comparisons reveal important changes in genome structure, genome size, and replication/gene regulation strategy during evolutionary history. In addition, the wide diversity of flavi-like viruses found in invertebrates, as well as their deep phylogenetic positions, suggests that they may represent the ancestral forms from which the vertebrate-infecting viruses evolved. For the vertebrate viruses, we expanded the previously mammal-only pegivirus-hepacivirus group to include a virus from the graceful catshark (Proscyllium habereri), which in turn implies that these viruses possess a larger host range than is currently known. In sum, our data show that the Flaviviridae infect a far wider range of hosts and exhibit greater diversity in genome structure than previously anticipated.
The family Flaviviridae of RNA viruses contains several notorious human pathogens, including dengue virus, West Nile virus, and hepatitis C virus. To date, however, our understanding of the biodiversity and evolution of the Flaviviridae has largely been directed toward vertebrate hosts and their blood-feeding arthropod vectors. Therefore, we investigated an expanded group of potential arthropod and vertebrate host species that have generally been ignored by surveillance programs. Remarkably, these species contained diverse flaviviruses and related viruses that are characterized by major changes in genome size and genome structure, such that these traits are more flexible than previously thought. More generally, these data suggest that arthropods may be the ultimate reservoir of the Flaviviridae and related viruses, harboring considerable genetic and phenotypic diversity. In sum, this study revises the traditional view on the evolutionary history, host range, and genomic structures of a major group of RNA viruses.
The leaf area index（LAI） is an important vegetation parameter,which is used widely in many applications.Remote sensing techniques are known to be effective but inexpensive methods for estimating the ...LAI of crop canopies.During the last two decades,hyperspectral remote sensing has been employed increasingly for crop LAI estimation,which requires unique technical procedures compared with conventional multispectral data,such as denoising and dimension reduction.Thus,we provide a comprehensive and intensive overview of crop LAI estimation based on hyperspectral remote sensing techniques.First,we compare hyperspectral data and multispectral data by highlighting their potential and limitations in LAI estimation.Second,we categorize the approaches used for crop LAI estimation based on hyperspectral data into three types：approaches based on statistical models,physical models（i.e.,canopy reflectance models）,and hybrid inversions.We summarize and evaluate the theoretical basis and different methods employed by these approaches（e.g.,the characteristic parameters of LAI,regression methods for constructing statistical predictive models,commonly applied physical models,and inversion strategies for physical models）.Thus,numerous models and inversion strategies are organized in a clear conceptual framework.Moreover,we highlight the technical difficulties that may hinder crop LAI estimation,such as the ＂curse of dimensionality＂ and the ill-posed problem.Finally,we discuss the prospects for future research based on the previous studies described in this review.
At the end of 2019 Wuhan witnessed an outbreak of "atypical pneumonia" that later developed into a global pandemic. Metagenomic sequencing rapidly revealed the causative agent of this outbreak to be ...a novel coronavirus denoted SARS-CoV-2. To provide a snapshot of the pathogens in pneumonia-associated respiratory samples from Wuhan prior to the emergence of SARS-CoV-2, we collected bronchoalveolar lavage fluid samples from 408 patients presenting with pneumonia and acute respiratory infections at the Central Hospital of Wuhan between 2016 and 2017. Unbiased total RNA sequencing was performed to reveal their "total infectome", including viruses, bacteria and fungi. We identified 35 pathogen species, comprising 13 RNA viruses, 3 DNA viruses, 16 bacteria and 3 fungi, often at high abundance and including multiple co-infections (13.5%). SARS-CoV-2 was not present. These data depict a stable core infectome comprising common respiratory pathogens such as rhinoviruses and influenza viruses, an atypical respiratory virus (EV-D68), and a single case of a sporadic zoonotic pathogen-Chlamydia psittaci. Samples from patients experiencing respiratory disease on average had higher pathogen abundance than healthy controls. Phylogenetic analyses of individual pathogens revealed multiple origins and global transmission histories, highlighting the connectedness of the Wuhan population. This study provides a comprehensive overview of the pathogens associated with acute respiratory infections and pneumonia, which were more diverse and complex than obtained using targeted PCR or qPCR approaches. These data also suggest that SARS-CoV-2 or closely related viruses were absent from Wuhan in 2016-2017.
Although segmented and unsegmented RNA viruses are commonplace, the evolutionary links between these two very different forms of genome organization are unclear. We report the discovery and ...characterization of a tick-borne virus—Jingmen tick virus (JMTV)—that reveals an unexpected connection between segmented and unsegmented RNA viruses. The JMTV genome comprises four segments, two of which are related to the nonstructural protein genes of the genus Flavivirus (family Flaviviridae), whereas the remaining segments are unique to this virus, have no known homologs, and contain a number of features indicative of structural protein genes. Remarkably, homology searching revealed that sequences related to JMTV were present in the cDNA library from Toxocara canis (dog roundworm; Nematoda), and that shared strong sequence and structural resemblances. Epidemiological studies showed that JMTV is distributed in tick populations across China, especially Rhipicephalus and Haemaphysalis spp., and experiences frequent host-switching and genomic reassortment. To our knowledge, JMTV is the first example of a segmented RNA virus with a genome derived in part from unsegmented viral ancestors.
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